I've worked on some minor fixes, added a new command and greatly improved the API and its documentation.

A full list of changes:
- Fix /statz not showing custom stat pages even though it was turned on in the config.
- Started working on support for disabling statistics in Worldguard regions or GriefPrevention claims.
- Statz now records HUSKs and STRAYs.
- Fix Statz not counting mobs killed with a bow as being killed by a player
- Fix votes still being counted even though you had it disabled in the config.
- Added /statz purge <time> command to remove players from the database that have not been online for a while. For more info, click here.
- Instead of the regular statz.list permission, I have now split the permission into two: statz.list.self and statz.list.others to check your own stats and those of others respectively.

Updates for developers:
- Other plugins can now obtain data more easily by listening to the UpdateDataEvent that Statz fires when it updates its database.
- I have added a lot of new examples and documentation on new methods and already existing ones.
- I've updated the API page on the wiki on Github. Please read it and see if you are missing anything!